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E. A. ROEHL.

METHOD OF MAKING PISTON RINGS.

APP LICATIO N FILED AUG-6,1917- 1,322,056. Patented Nov. 18, 1919.

[/7 yen/or Edward A 9066/ fi/forney STATES EDWARD A. WHEEL, OF ST. PAUL, MINNESOTA.

MJE'IHUD OF MAKING PISTON-RINGS.

Specification of Letters Patent.

Patented Nov. 18, 1919..

application filed August G, 19173 Serial No. 184,776.

.ternal combustion engines and the like.

With this and incidental objects in view the invention consists of certain novel methods and sequences of operations, the essential elements of which are hereinafter described with reference to the drawing which accompanies and forms a part of this specification.

In the drawing Figure 1 is a side elevation of my improved piston ring; Fig. 2 is a plan view of the same, and Fig. 3 is a detail of the lap portion formed by an alternate method. Fig. l is a side elevation of a helical. spring having a considerable number of convolutions and showing how the spring is to be cut into individual springs for forming the piston rings.

My invention contemplates broadly. the forming of a piston ring that shall have two complete convolutions to more thoroughly seal the engine cylinder in which'it is used than does the common type of ring.

ll' hile piston rings have been made heretofore having two or more convolutions. I believe that my method of producing the ring is entirely new.

When the ring is to be made of steel or other suitable material capable of being formed, I prefer to form a helical spring having a large number of convolutions as shown in Fig. 4 and then cut this spring into a number of individual springs, each. having two complete convolutions.

With the individual springs so cut each is placed in a die and by exerting pressure upwardly in the direction of the arrow 1, Fig. I, and. downwardly as indicated by the arrow 2 with the portions 3 and d of the ring maintained in a horizontal position, a double bend is formed with an angle at 5 fitting the angle at which the end 6 of the ring has been out 0d", and with the angle at 7 fitting the similar angle at which the end 8 has been cut ed.

When making rings of metal of this type, the method described is extremely low in manufacturing cost as it is only necessary to form up the springs, make the individual cuts at the proper angle, and then strike the individual ring so formed in a die, thus com pleting the piston ring, which may be turned or ground later or not as desired.

When a cast iron ring is desired I form my improved ring in a somewhat diflerent manner.

Two individual rings are turned of cast iron in the ordinary manner and each of the rings is then cut on an angle, as shown in Fig. 3.

After the rings have been so formed they are positioned with the ends as shown in Fig. 3, and a portion 9 of each of the rings is then welded together thus forming one complete ring having two convolutions. It is apparent that the lap at 9 may be of any suitable length, the new feature of this method being the welding of two such rings at their opposite extremities so as to form thereby a single ring having two convolutions. y

While I have described my invention and illustrated it in two particular designs, I do not wish it understood that I limit myself to these methods, as it is evident that the application of my invention may be varied in many ways within the scope of the following claims.

Claims:

1. The method of forming piston rings comprising the forming of a rod of rectan gular section into a helical spring, cutting the helical spring into individual springs having two convolutions. and forming the central portion of the individual springin a die so as to bring the outer ends of the helical spring into two respective parallel planes.

2. The method of forming piston rings comprising the. forming of a rod of rectangular section into a helical spring, cutting the spring by diagonal cuts into individual springs, having two convolutions, and forming the central portion of the individual springs transversely between the diagonally cut ends to produce a piston ring having its edges parallel.

EDWARD A. nonnn. 

